.alpha.-chloroacetoacetanilide is an important intermediate in the preparation of carboxin which is an agent used to control numerous plant diseases. See, e.g., U.S. Pat. No. 3,249,499.
The chlorination of acetoacetanilide compounds with chlorine to produce .alpha.-chloroacetoacetanilide compounds is cheaper than using other chlorinating agents such as sulfuryl chloride but has the disadvantage of being non-selective and giving large quantities of by-product .alpha.,.alpha.-dichloroacetoacetanilide compounds and unreacted acetoacetanilide compounds.
Attempts to overcome this problem have been described. For example, U.S. Pat. No. 3,852,351 describes the reaction of acetoacetamides with chlorine to form the corresponding .alpha.-chloro compound. The reaction takes place in a substantially anhydrous reaction medium consisting of a polar solvent and a compound which causes enolization, such as a Lewis acid or chelates.
Czechoslavakian Patent Document 170709 describes a method for synthesizing .alpha.-chloroacetoacetanilide by chlorinating acetoacetanilide with elemental chloride in a medium consisting of an organic solvent (methanol or tetrachloromethane) or a mixture of such an organic solvent with hydrochloric acid or glacial acetic acid.